Addition Of Alcohol Research Articles

Effect of solvation-dehydration of quaternary ammonium base salts in the organic phase on the selectivity of anion-exchange extraction

ABSTRACT The analysis of the influence of dehydration and solvation (by proton-donor reagents) of halide anions in the organic phase on the processes of their solvent extraction separation with salts of quaternary ammonium bases has been carried out. The possibility of a significant increase in the separation factors of anions in the F-Cl-Br-I series due to endothermic dehydration of amine salts (Aliquat 336) in systems with “weak” proton-donor reagents, such as chloroform has been shown. In particular, the separation factors of the Cl/F pair increase by almost 15 times when going from Aliquat 336 solutions in toluene to extractant solutions in chloroform, for the Br/Cl pair, this increase is up to 5 times, and for I/Cl, about 3 times. In similar systems with additions of alcohols and phenols to the extractant (exothermic dehydration), there is a significant deterioration in the separation parameters of halides. The conclusions are confirmed by the data of 1H NMR studies, which also made it possible to establish some details of the processes of dehydration of amine salts in the studied systems.

Auto-ignition propensity of ethanol-, isobutanol-, and 2-methyl-3-buten-2-ol-gasoline blends under premixed prevaporized conditions in a spark-ignition engine

The effects of alcohol addition to gasoline on knock-limited operation were studied in an internal combustion engine. Ethanol, isobutanol (2-methyl-1-propanol), and methylbutenol (2-methyl-3-buten-2-ol) were splash-blended with a gasoline blendstock for oxygenate blending (BOB) and supplied to the engine in a well-mixed gaseous state. By operating the engine in this way, the chemical anti-knock properties of the fuel could be studied without including physical effects such as evaporative cooling. Each alcohol was blended with the BOB to make three blends. Ethanol was blended at 10, 20, and 30% by volume (E10, E20, and E30). Isobutanol and methylbutenol blends were matched to ethanol on an oxygen weight percentage basis resulting in blends of 16, 32, and 49% (I16, I32, and I49) and 18, 37, and 56% (M18, M37, and M56) by volume for isobutanol and methylbutenol, respectively. Additional fuels tested for reference included the neat BOB, a Tier 3 E10 emissions certification gasoline as well as primary reference fuels (PRF) with octane ratings of 87 (PRF87) and 100 (PRF100). The engine was operated at a fixed speed and stoichiometric equivalence ratio while knock-limited spark advance was located across a range of loads. At low blend levels, ethanol and methylbutenol blends exhibited similar knock-limited combustion phasing, slightly advanced from isobutanol. At mid-blend levels, the difference in combustion phasing of methylbutenol and ethanol over isobutanol increased further. At the highest blend level, ethanol and isobutanol showed approximately equal performance. Conversely, methylbutenol was able to operate at significantly advanced combustion phasing relative to the other two alcohols. At loads above 900 kPa gross indicated mean effective pressure (GIMEP), M56 exceeded the knock-limited combustion phasing of PRF100. The overall results of this study show that when compared on an oxygen weight percent basis, the order of chemical auto-ignition resistance for the three alcohols is isobutanol < ethanol < methylbutenol, with methylbutenol matching or exceeding ethanol’s knock-limited performance across the load range tested.

Improvement of the analytical characteristics for the determination of impurities in high temperature nickel alloys using inductively coupled plasma - mass spectrometry (ICP-MS)

The results of studying the effect of alcohol additives (ethanol and isopropanol) on the analytical signals of 15 elements in their determination by the method of inductively coupled plasma-mass spectrometry (ICP-MS) are presented. It is shown that these additives lead to more than two-fold increase of the analytical signals from As, Se, and Те. The study of their effect on the formation of oxide ions of the main alloying components revealed the suppression of the formation of interfering polyatomic ions of chromium and titanium, the signals of which superimposed on the signal from 82Se. Harmful impurities in a complex alloyed sample of nickel alloy were determined using alcohol additives and other methods of suppressing spectral interferences. It is shown that determination of less than 2 pg/g of selenium necessitates the addition of 2 vol. % of ethyl alcohol. The correctness of the obtained results was confirmed by a comparative analysis of data obtained for the same sample by high resolution mass spectrometry with a glow discharge.

Total Synthesis of Starfish Cyclic Steroid Glycosides. Part 2, Model Synthesis via Intramolecular Etherification

Comprehensive SummarySepositoside A (1) is a prototypical cyclic steroid glycoside bearing a hybrid 16‐membered ring composed of the steroid skeleton and a 1,2‐trans‐linked trisaccharide. Herein, we report an expedient access toward two simplified analogues, in which the strained 16‐membered ring is constructed via Au(I)‐catalyzed intramolecular addition of alcohol to epoxide. A similar macroetherification in relevant steroid trisaccharides has been intensively examined, however, failed to furnish the macrocyclic skeleton of Sepositoside A.

Dimethyl ether from methanol on mesoporous γ-alumina catalyst prepared from surfactant free highly porous pseudo-boehmite

Different samples of mesoporous nano-sized γ-alumina were prepared through surfactant-free sol-gel process, using aluminum nitrate as precursor. The influence of variables such as addition of alcohol, metal salts and also effect of changing the aluminum source were investigated on the synthesis method. The products, which were obtained on different conditions, were then characterized by XRD, FT-IR, SEM, TEM. Moreover, textural properties were also measured by BET. To study thermal stability of prepared alumina; Cerium nitrate, magnesium nitrate, lanthanum nitrate and gadolinium nitrate were added as dopants. The catalytic performance of the synthesized mesoporous alumina (with a surface area of ​​272 m2/g, pore volume of 0.94 cm3/g and pore size of 13.8 nm) was studied for the methanol conversion to dimethyl ether, and the result was compared by commercial γ-alumina. Synthesized mesostructured catalyst has comparable activity and DME selectivity at 300°C to that of commercial alumina at 400 °C.

Novel technique to study the wet chemical etching response of multi-crystalline silicon wafers

The current work aimed to demonstrate the application of a technique where white light interferometry (WLI) and Laue X-ray crystallography scanner characterisation were combined to study the chemical etching response of diamond cut multi-crystalline Si (mc-Si) wafers. Using this technique, the effect of different texturing additives (isopropyl alcohol, natrium hypochlorite) was evaluated by examining the topography of the mc-Si surfaces before and after etching. The etching responses of monocrystalline Si wafers of (100), (110) and (111) orientations were used as reference for comparison with the multi-crystalline wafers investigated. The texturing results illustrated the influence of different crystal-orientations on the etching rate. It was revealed that for the mc-Si wafers, the etching speed of the different crystal grain-planes is increasing with their crystallographic similarity with the main (hkl) planes (100, 110,111). The comparison of isopropyl alcohol (IPA) and sodium hypochlorite (NaOCl) additives to KOH solutions showed that NaOCl additive is favourable for the polishing of mc-Si wafers, while IPA can be used as polishing only for crystal grains close to the (111) orientation.

Synthesis of Guaipyridine Alkaloids Rupestine M and L by Cycloaddition/Cycloreversion of an Intermediate 1,4-Oxazinone.

A new method to prepare 1,4-oxazinone intermediates was developed based on aza-conjugate addition of β-amino alcohols to electron-deficient alkyne precursors. A tandem intramolecular cycloaddition/cycloreversion reaction sequence was evaluated, leading to the synthesis of the guaipyridine alkaloid natural products rupestine M and L. Starting from (-)-citronellal and thus a known configuration of the C5 stereocenter, a revised absolute configuration of natural rupestine L is suggested based on optical rotation.

Experimental investigation of advanced nano materials additives on combustion characteristics of biofuels

Due to the depletion of fossil fuels, renewable and cleaner fuel is now required for diesel engines. The researchers are looking into different kinds of bio-based fuels. It is anticipated that biodiesel will compete with diesel fuel. Pure biodiesel can be used in diesel engines, but due to some drawbacks, including higher density, a lower cetane number, and a lower calorific value, it cannot completely replace conventional diesel. As a result, using biofuel blends in diesel engines is preferred. The role of nanoparticles in biofuel production and the impact of nanoparticles in biodiesel-diesel fuel blends on diesel engine performance, combustion analysis, and emission characteristics are covered in this paper in two different ways. This review study compiles a wide range of findings from earlier research studies on the potential and applications of nanoparticles in the production of bioethanol as well as the impact of their addition to diesel fuel at various biofuel ratios. There are numerous techniques for improving engine performance. Nanoparticles can be used as catalysts in chemical reactions and feedstock pretreatment processes to produce biofuels. According to the overall findings, adding nanoparticles significantly reduced the amount of fuel used for brakes by 20% to 23% when compared to biodiesel-diesel blends with and without the addition of alcohol. In addition to improving the combustion process and boosting the brake power by 2.5% to 4%, nanoparticles have a high thermal conductivity. Emission results revealed that while HC, CO, and PM emissions all significantly decreased in most reviews, NO emissions increased by up to 55%. According to the study's findings, adding nanoparticles to biodiesel and its blends as fuel can make diesel engines run more efficiently, deliver better performance, and produce emissions that are effectively regulated.

The role of cholesterol in curvature and stripe width evolution in model lung surfactant monolayers.

Lung surfactant (LS) is a lipid-protein monomolecular layer coating the alveolar air-liquid interface. A primary role of LS is to reduce the interfacial tension to facilitate breathing. Simple two and three component systems are used to model LS in studies to test the relationship between composition, morphology, rheological, and phase behavior. Failure of LS is associated with acute respiratory distress syndrome (ARDS). The primary lipid in LS is dipalmitoylphosphatidylcholine (DPPC) which accounts for 40-80 percent of native and replacement LS therapies. The addition of fatty acids, fatty alcohols, and cholesterol to replacement LS therapies is still an area of research. We utilize mixtures of DPPC and hexadecanol (HD) or palmitic acid (PA) with small mole fractions of dihydrocholesterol (DChol). The morphology of 2-dimensional self-assembled monolayers with coexisting crystalline-like domains (liquid-condensed phase) within a liquid-like matrix (liquid-expanded phase) is investigated. With the addition of DChol to the DPPC/HD or DPPC/PA system, a finger instability is seen during monolayer compression followed by a time dependent circle-to-stripe transition at a fixed interfacial tension. In this poster we will discuss recently published results on the equilibrium nature of these films (REF: Valtierrez et al., Sci. Adv. v:8:14, 2022) and extend this work to explore the role of cholesterol in determining morphology and curvature.

Enzymatic Transesterification of Atlantic Salmon (Salmo salar) Oil with Isoamyl Alcohol.

In this experimental study, biodiesel was synthesized from the salmon oil using the Lipozyme®RM IM (Bagsværd, Denmark) as a biocatalyst. Isoamyl alcohol was used as an acyl acceptor in the transesterification process. The aim of this study is to select the best process conditions, aiming to obtain the highest transesterification degree that meets the requirements of the EN 14214 standard. Response surface methodology (RSM) was used for statistical analysis and optimization of process parameters. A four-factor experimental design was modelled by central compositional design (CCD) to investigate the effects of biocatalyst concentration, isoamyl alcohol-to-oil molar ratio, temperature, and duration on transesterification degree. It was determined that the optimal parameters for biodiesel synthesis were the following: an enzyme concentration of 11% (wt. of oil mass); a process temperature of 45 °C; a process duration of 4 h; and an alcohol-to-oil molar ratio of 6:1. The transesterification degree of biodiesel reached 87.23%. The stepwise addition of isoamyl alcohol during the transesterification process further increased the degree of transesterification to 96.5%.

Ring-Opening Polymerization of rac-Lactide Catalyzed by Octahedral Nickel Carboxylate Complexes

To date, nickel(II) complexes have not been practically investigated as catalysts in ring-opening polymerization (ROP) of lactide to produce biodegradable poly(lactic acid), which is in demand in biomedicine and industry. In this study, carboxylate complexes of nickel(II) containing various N-donor ligands with different nuclearity, metal core rigidity and nature of carboxylate ligands were synthesized and studied by infrared spectroscopy, X-ray diffraction, elemental and thermogravimetric analyses. The obtained complexes were examined in the ROP of the rac-lactide in bulk and in toluene solution with and without the addition of a benzyl alcohol initiator. In the series of complexes studied, the complex [Ni(DBED)2(O2CC(CH3)3)2]·(CH3)3CCO2H (DBED is N,N′-dibenzylethylenediamine) was a syndioselective catalyst and showed the highest catalytic ability in the polymerization without the addition of benzyl alcohol. For this complex, according to 1D DOSY 1H NMR spectroscopy and mass spectrometry with electrospray ionization, polymerization is initiated by a free secondary amine, DBED, leaving the metal’s inner coordination sphere. Based on the experimental data obtained, a comprehensive density functional theory (DFT) study of the ROP pathways including the initiation and first chain growth cycle steps with a detailed description of the intermediates and evaluation of the energy barriers of the steps was carried out. It was shown that one of the key roles in the reaction process is played by carboxylate ligands, which act as proton carriers from the initiator molecule and have a significant influence on the reactivity of the catalytic metal complexes.

Voriconazole Eye Drops: Enhanced Solubility and Stability through Ternary Voriconazole/Sulfobutyl Ether β-Cyclodextrin/Polyvinyl Alcohol Complexes.

Voriconazole (VCZ) is a broad-spectrum antifungal agent used to treat ocular fungal keratitis. However, VCZ has low aqueous solubility and chemical instability in aqueous solutions. This study aimed to develop VCZ eye drop formulations using cyclodextrin (CD) and water-soluble polymers, forming CD complex aggregates to improve the aqueous solubility and chemical stability of VCZ. The VCZ solubility was greatly enhanced using sulfobutyl ether β-cyclodextrin (SBEβCD). The addition of polyvinyl alcohol (PVA) showed a synergistic effect on VCZ/SBEβCD solubilization and a stabilization effect on the VCZ/SBEβCD complex. The formation of binary VCZ/SBEβCD and ternary VCZ/SBEβCD/PVA complexes was confirmed by spectroscopic techniques and in silico studies. The 0.5% w/v VCZ eye drop formulations were developed consisting of 6% w/v SBEβCD and different types and concentrations of PVA. The VCZ/SBEβCD systems containing high-molecular-weight PVA prepared under freeze-thaw conditions (PVA-H hydrogel) provided high mucoadhesion, sustained release, good ex vivo permeability through the porcine cornea and no sign of irritation. Additionally, PVA-H hydrogel was effective against the filamentous fungi tested. The stability study revealed that our VCZ eye drops provide a shelf-life of more than 2.5 years at room temperature, while a shelf-life of only 3.5 months was observed for the extemporaneous Vfend® eye drops.

Addition of Alcohols onto Electron-Deficient Heteroarenium Salts: A Reversible Covalent Bonding Process under Basic Conditions

AbstractThe reversible addition of benzyl alcohol onto heteroarenium salts under basic conditions was studied. Fine-tuning of the nature of the arenium and substituents allowed the discovery of a range of pyrimidinium substrates that can undergo C6-selective alcohol addition. Crossover experiments were also performed to confirm the addition-elimination equilibrium under basic conditions.

Adsorption properties and physical characterization of carrageenan/alginate macro and microspheres blended with flexible chain polymers

This work addresses the production and characterization of alginate-carrageenan matrixes, cross-linked with epichlorohydrin in the presence of different flexible chain polymers: polyvinyl alcohol and polyvinyl pyrrolidine. These matrixes were obtained by ionotropic gelation in two different sizes: macro and microspheres. The different systems were characterized by optical microscopy, SEM and TGA. The obtained matrixes showed differences in their water content, shape and roughness due to the addition of flexible chain polymers into their composition.These matrixes were used for the adsorption of lysozyme. The adsorption process was found to follow a first order kinetics model and was not influenced by the type of polymer attached. In addition, the Langmuir model was the most suitable isotherm model for our data. The addition of polyvinyl alcohol and polyvinyl pyrrolidone decreases the adsorption capacity of the original matrixes, in both macro and micro scale. Finally, it was shown that when decreasing the size of the spheres, their adsorption capacity increases up to 5 times.

Spark Plasma Sintering of Ceramics Based on Solid Solutions of Na1+2xZr2−xCox(PO4)3 Phosphates: Thermal Expansion and Mechanical Properties Research

The structure, microstructure, coefficient of thermal expansion (CTE), and mechanical properties of Na1+2xZr2−xCox(PO4)3 ceramics (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) were studied. Na1+2xZr2−xCox(PO4)3 submicron powders with the NaZr2(PO4)3 structure (NZP, kosnarite type) were obtained by the solid-phase method. The starting reagents (NaNO3, ZrOCl2·8H2O, NH4H2PO4, CoCl2·6H2O, ethanol) were mixed with the addition of ethyl alcohol. The resulting mixtures were annealed at 600 °C (20 h) and 700 °C (20 h). The obtained phosphates crystallized in the expected structure of the NaZr2(PO4)3 type (trigonal system, space group R3¯c). Thermal expansion of the powders was studied with high-temperature X-ray diffraction at temperatures ranging from 25 to 700 °C. CTEs were calculated, and their dependence on the cobalt content was analyzed. Na1+2xZr2−xCox(PO4)3 ceramics with high relative density (93.67–99.70%) were obtained by Spark Plasma Sintering (SPS). Ceramics poor in cobalt (x = 0.1) were found to have a high relative density (98.87%) and a uniform fine-grained microstructure with a grain size of 0.5–1 µm. Bigger cobalt content leads to a smaller relative density of ceramics. During the sintering of ceramics with high cobalt content, anomalous grain growth was observed. The powder compaction rate was shown to be determined by creep and diffusion intensity in the Na1+2xZr2−xCox(PO4)3 crystal lattice. SPS activation energy in ceramics increased as the cobalt content grew. The microhardness and fracture toughness of ceramics did not depend on their cobalt content.

Zn(II)-catalysed enantioselective addition of alcohols and tert-butyl hydroperoxide to isatin-derived N-Boc ketimines.

Using binaphthyl-proline-based chiral ligands, Zn(II)-catalysed addition of alcohols and tert-butyl hydroperoxide to isatin-derived N-Boc ketimines provided the isatin-derived C3 N,O-aminals in up to 99% yield and up to 99% ee. The reactions could be carried out under mild conditions and a gram-scale reaction could be realized without the loss of the yield and enantioselectivity.

Kinetics of biodegradation of strengthening polymer systems based on copolymers of lactic acid and biogenic activators

The production of bioplastics based on copolymers of maleic anhydride with the addition of lactic acid and furyl alcohol is described. The obtained copolymers are promising for use as reinforcing polymer systems of cellulose-containing materials used in packaging. It has been shown that the use of lactic acid and furyl alcohol makes it possible to obtain synthetic bioplastics that are rapidly degradable in natural conditions, which is favorable for environmental protection.

Understanding the performance, emissions, and combustion behaviors of a DI diesel engine using alcohol/hemp seed oil biodiesel/diesel fuel ternary blends: Influence of long-chain alcohol type and concentration

In this study, it was aimed to examine the influences of biodiesel–diesel-higher alcohol (1-pentanol, 1-hexanol, and 1-heptanol) blends on the performance, emission and combustion behaviors of a single-cylinder diesel engine. The tests were performed at a fixed speed of 1500 rpm and variable loads (25%, 50%, 75%, and 100%). For the tests, 80% diesel and 20% hemp seed oil biodiesel were blended and called as B20. Biodiesel fuel was produced by transesterification from hemp seed oil in the presence of methanol and potassium hydroxide for the preparation of B20 binary test fuel and other ternary fuels. Furthermore, nine ternary blend fuels [20% HSOB + 70%, 60% and 50% diesel, respectively + 10%, 20% and 30% higher alcohol (pentanol, hexanol and heptanol) respectively] were prepared. The calculations made with the experimental data revealed that the minimum brake specific energy consumption values were 12,48 MJ/kW h, 13,06 MJ/kW h, 13,27 MJ/kW h, 13,35 MJ/kW h, 13,47 MJ/kW h, and 13,59 MJ/kW h, respectively, for diesel fuel at full load, for fuels B20, B20Hx10, B20Hp10, B20Hx20 and B20Pe10, the maximum brake thermal efficiency values were obtained as 28.85%, 27.56%, 27.14%, 26.97%, 26.73% and 26.49%, respectively, for the same fuels at the same load. The increment in higher alcohol concentration in the blend delayed start of combustion and therefore the ignition delay period was prolonged. In the fuel line pressure data, changes were observed depending on the amount, viscosity and density of the fuel. Furthermore, B20Hx10 and B20Hp10 fuels gave the maximum in-cylinder pressure, heat release rate, average gas temperature and pressure rise rate values after diesel and biodiesel. The addition of biodiesel and higher alcohol to diesel fuel resulted in a decrease in NOX, CO and unburned HC and smoke emissions and an increase in CO2. NOX, CO and unburned HC values of higher alcohol blended fuels at full load showed lower results, between 3.04–22.24%, 22.85–56.35% and 5.44–22.83%, respectively, compared to diesel fuel. It can be concluded that the use of hemp seed oil biodiesel and higher alcohol in the diesel engine will make a significant contribution to the reduction of NOX emissions.

Reduction of SF5CF3via iridium catalysis: radical trifluoromethylation of aromatics.

The greenhouse gas SF5CF3 acts as CF3 source for the photocatalytic trifluoromethylation of arenes on using [Ir(dtbbpy)(ppy)2]PF6 (4,4'-di-tert-butyl-2,2'-dipyridyl, ppy = 2-phenylpyridine) as catalyst. The trifluoromethylation of C6D6 in the presence of 1-octanol results in the concomitant generation of 1-fluorooctane, presumably by intermediate SF4.

Combustion and Performance Evaluation of Methanol (M15)-Fueled BS-VI Compliant Light-Duty Spark-Ignition Engine

Abstract This study investigated the effect of the methanol–gasoline blend (M15) on the combustion and performance characteristics of a commercial light-duty Bharat Stage-VI (BS-VI) 2020 spark-ignition (SI) engine. The M15 and baseline gasoline (G100) engine tests were performed at a wide range of engine loads and speeds. For the M15 operation, it was ensured that the lambda values matched with the baseline gasoline operation at each engine operating point by changing fuel quantity manually. The combustion characteristics of M15 were quite similar to gasoline at all operating points. Alcohol addition improves octane number and flame speed, which changes the combustion characteristics of the engine, but in this study, the combustion characteristics of M15 fuel were almost identical. It may be due to blending a small fraction of methanol and the engine's high compression ratio, which improved the combustion kinetics. The coefficient of variance of indicated mean effective pressure was slightly lower for M15 than gasoline, except at 1000 rpm, where the charge mixing might not be adequate at low engine speed for M15 due to lower methanol volatility. Engine's brake thermal efficiency improved with M15 fueling by ∼1%, compared to baseline gasoline, though brake-specific fuel consumption deteriorated by ∼6% due to the lower calorific value of M15. Higher combustion stability and possibly lower heat transfer losses, as observed from slightly higher exhaust gas temperature (EGT), might have improved the engine's performance for M15. This study demonstrated that M15 fueling exhibited identical combustion characteristics and higher thermal efficiency than baseline gasoline fueling at similar lambda values in a commercial light-duty BS-VI SI engine.